how to concatenate

Hello every one

Can you please help with the below scenario

1 A

1 B

1 C

2 D

2 E

3 F

I need output like

1 ABC

2 DE

3 F

CREATE TABLE [dbo].[Teja](
	[value] [smallint] NOT NULL,
	[alpha] [nchar](10) NOT NULL
) ON [PRIMARY]

insert into teja(value,[alpha])
select 1,'a'
union all
select 1,'b'
union all
select 1,'c'
union all
select 2,'d'
union all
select 2,'e'
union all
select 3,'f'
union all
select 4,'g'
union all
select 4,'h'

CAN ANY ONE PLEASE HELP

Thanks

KUMAR